The present invention relates to a push-pull connector assembly whose basic features are at least spray tightness, a little immersion of said assembly being preferably admitted. The connector assembly comprises a connector and an outlet The invention also relates to the connector alone. The object of the invention is to use existing push-pull connectors, and to modify them as little as possible in order to be able to use previously developed industrial tools.
A push-pull connector is a connector whose connection to an outlet is obtained by pushing the connector therein. Once it is connected, the connector is automatically locked to the outlet. Particularly, by pulling the cable attached thereto, the connector cannot be normally hooked off. In order to uncouple the connector from the outlet, what has to be seized is not the cable but a release socket forming the outer envelope of the connector and being placed near said outlet. By pulling back the release socket, the mechanical connection is released and the connector and the outlet can be uncoupled. Such push-pull connectors are equally useful for electric, optical, and pneumatic connections. Their structure is such that they comprise a first socket, named spring socket, covered by the release socket, which is more directly in contact with the outlet. The first socket is a spring socket because, in the rest position, it has the effect of forcing back the release socket so that it is spaced therefrom. The two sockets slightly slide one onto the other to allow such movements.
The basic problem encountered with these push-pull connectors relates to the mechanism for coupling and ID uncoupling them to the outlet. They are not watertight, and not even spraytight. So, they do not comply with the IP55 standard and even less with the IP67 standard, which requires watertightness in conditions of temporary immersion in water fifteen centimeters deep. In fact, water or dust may infiltrate between sliding parts. By placing a joint where sliding occurs between the spring socket and the release socket, any relative movement of the two parts is naturally impeded. Hence, this joint may ensure watertightness, but the friction caused thereby prevents the release socket from getting back to its rest position under the action of the spring of the spring socket, when the thrust which pushes it towards the spring socket is released. Otherwise, friction is weak, and the relative movements are not prevented, but in this case no watertightness is provided.
In the invention, this drawback has been obviated by choosing a different joint shape. The joint of the invention is not a sliding joint. On the contrary, the joint of the invention is an elastic joint being able to take two positions. This elastic joint has edges in permanent contact with each of the sockets. This elastic joint substantially has the shape of a bellows. In a first condition, corresponding to the rest position, when the release socket is at a distance from the spring socket, the bellows is stretched, and the joint is extended. When the release socket is driven closer to i the spring socket, a stress is exerted on the elastic joint, and the bellows is folded. The elastic joint is nevertheless in permanent contact with the spring socket and with the release socket. Hence, it provides a watertight connection between these two parts. Further, when the joint is folded, it naturally tends to return to its unfolded shape. So, in these conditions it exerts a thrust tending to force back the release socket, away from the spring socket. In this manner, the joint assists the locking effort, instead of limiting the relative displacements of the two parts, as provided in prior art. The result is achieved that, besides obtaining watertightness, the relative elasticity of the two parts is not reduced, but even increased.
Hence, the invention relates to a push-pull connector comprising a plug provided with a spring socket and with a release socket, characterized in that it has a watertight cylindrical elastic joint, placed between the spring socket and the release socket, the elastic joint consisting of a bellows, delimited by two ribs, the spring socket and the release socket having each a circular groove for accommodating one of these ribs, the elastic joint being in a stressed condition when the release socket is forced back against the spring socket and in a rest condition when the release socket is uncoupled from the spring socket.
The invention also relates to a push-pull connector assembly comprising such a connector and an outlet, the outlet being designed to accommodate the plug, characterized in that the outlet has a plate with a circular groove and a toric joint in this groove.